Using Genomic Tools for the Identification of Important Signaling Pathways in Order to Facilitate Cell Culture Medium Development

Abstract

Given the diversity of cells grown in culture and the fact that each of these cultures is poised to respond to a variety of stimuli, we set out to establish a method to identify these important pathways to accelerate the development of cell culture media. Many of the pathways required for cell functions (i.e. cell proliferation, protein production, cell adhesion, etc.) have been elucidated in detail, but there are undoubtedly unknown pathways, which may also be involved. Identification of these resources allows us to better understand these processes and potentially manipulate them to our advantage. In order to validate this concept, we identified the mRNA expression profile for a variety of proteins within cells in culture using cDNA microarrays. In one example, we identified a specific growth factor receptor not previously known to be expressed in vitro. When the ligand for this receptor is added to the culture, the cells are poised to respond and proliferate at an increased rate. This method has been used on a variety of culture systems to either reduce (or eliminate) FBS requirements or to improve the performance of already serum-free formulations. This more targeted approach to medium development allows us to perform less of the random screening approaches of the past, thereby decreasing the investment of time and resources into this endeavor.